1. Field of the Invention
This invention relates to a liquid crystal display device. More particularly, the invention relates to a liquid crystal display device for color display, having color filters.
2. Description of the Related Art
A liquid crystal display device for color display includes color filters that exhibit colors respectively corresponding to pixel regions formed on a surface of one of substrates so arranged as to oppose each other through a liquid crystal, on the liquid crystal side.
A black matrix having an aperture at its center other than a slight peripheral portion of each pixel region is generally formed on the surface of one of the substrates described above on the liquid crystal side in such a fashion as to define each pixel region.
Therefore, color filters having the same color are formed in common to a group of pixels juxtaposed in a y direction, for example, of each pixel region which is arranged in a matrix form, and overlap with adjacent color filters of other colors on the black matrix.
In the liquid crystal display device having the construction described above, however, it has been desired to eliminate the necessity for forming the black matrix so as to further improve the aperture ratio.
Nonetheless, because the black matrix has a function of improving contrast of display and a function of cutting off the rays of light in regions other than a liquid crystal display region, it has been a problem as to how to keep these functions.
It is therefore an object of the invention to provide a liquid crystal display device without a black matrix while providing the functions of the black matrix.
It is another object of the invention to provide a liquid crystal display device capable of maintaining a thickness of a liquid crystal layer at a suitable level.
The following will briefly illustrate typical examples of the inventions disclosed in this application.
According to a first embodiment of a liquid crystal display device of the present invention, there is provided, for example, a pair of substrates delimiting a pixel region and a peripheral region and a plurality of gate signal lines and a plurality of drain signal lines formed on the pixel regions of one of the pair of substrates and a gap control film formed on at least the one of the pair of substrates and a plurality of color filters formed on the other of the pair of substrates and a plurality of spacers formed on a surface of either one of the pair of substrates. At least two of the plurality of color filters are laminated in the peripheral region and the gap control film is removed at least at portions of the plurality of spacers arranged in the peripheral region.
According to a modification of the first embodiment of the liquid crystal display device of the present invention, for example, in the peripheral region is free of the gap control film over the entirely thereof.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of color filters comprise a red color filter, a green color filter and a blue color filter, and each of the plurality of color filters is formed along the plurality of drain signal lines in the pixel regions.
According to a further modification of the first embodiment of the liquid crystal display device of the present invention, for example, two of the plurality of color filters are laminated in the peripheral region. According to a further modification, the two of the plurality of color filter are the red color filter and the blue color filter. According to a further modification of the first embodiment of the liquid crystal display device of the present invention, for example, a thickness of the gap control film is in a range of 50% to 100% of a thickness of a single color filter in the display region.
According to another modification, three of the plurality of color filters are laminated in the peripheral region and the three of the plurality of color filters are the red color filter, the green color filter and the blue color filter. According to a further modification of the first embodiment, for example, a thickness of the gap control film is in a range of 100% to 200% of a thickness of the color filter of a lower layer of the laminated plurality of color filters.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, each of the plurality of color filters in the display region forms a boundary portion with adjacent one of the plurality of color filters having a different color so that opposing side wall surfaces thereof are one of proximate to each other and in contact with each other, the boundary portion being positioned above one of the plurality of drain signal lines. According to a further modification of the first embodiment, for example, the other substrate of the pair of substrates is configured so as to be free of a black matrix thereon. According to a further modification of the first embodiment, for example, the plurality of drain signal lines are made of non-light-transmitting conductive material.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of color filters comprise a red color filter, a green color filter and a blue color filter, and each of the plurality of color filters is formed along one of the plurality of gate signal lines and the plurality of drain signal lines in the display region, and each of the plurality of color filters forms a boundary portion with adjacent one of the plurality of color filters having a different color so that opposing side wall surfaces thereof are one of proximate to each other and keep contact with each other and the boundary portion being positioned above one of the plurality of gate signal lines and one of the plurality of the drain signal lines. According to a further modification of the first embodiment, for example, the other substrate of the pair of substrates is configured so as to be free of a black matrix thereon.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the gap control film comprises a layer made of an organic material.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of spacers are formed of resin which is etched by photolithography.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of spacer are formed in a plurality of pixel regions on the one of the pair of substrates.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of spacers are formed on the plurality of drain signal lines.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of spacers are formed on the other substrate of the pair of substrate.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the gap control film is formed on the display region and the peripheral region, and the peripheral region is free of the gap control film at each portion of the plurality of spacers.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, a protective film made of inorganic material is formed between the gap control film and the plurality of drain signal lines.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the plurality of spacers are formed on the protective film.
According to another modification of the first embodiment of the liquid crystal display device of the present invention, for example, the gap control film is formed on the one substrate and the other substrate of the pair of substrate. And According to a further modification of the first embodiment, the plurality of spacers are formed on the other substrate of the pair of substrate. According to a further modification of the first embodiment, the gap control film is a protective film made of an organic material.
According to a second embodiment of the liquid crystal display device of the present invention, for example, a plurality of gate signal lines formed in juxtaposition with one another on a surface of one of a pair of substrates arranged so as to oppose each other through a liquid crystal on the side of said liquid crystal, and a plurality of drain signal lines juxtaposed with one another so as to cross said gate signal lines, said gate signal lines and said drain signal lines together delimiting pixel regions in a display region.
Color filters are formed on a surface of an other of said pair of substrates on the side of said liquid crystal and exhibit a common color to each of said pixel regions juxtaposed with one another along either one of said gate signal lines and said drain signal lines and said color filter forms a boundary portion with an adjacent one of said color filters having a different color so that opposing side wall surfaces thereof are one of proximate and in contact with each other and said boundary portion is positioned above said lines.
At least two layers of said color filters having different colors are formed and laminated in a region other than the display region and a gap control film is formed on both of said gate signal lines and said drain signal lines on a surface of one of said substrates on the side of said liquid crystal and a film thickness of said gap control film at least substantially equal to a film thickness of one of a lower layer of said color filters laminated.
Pole-like spacers are formed on a surface of either one of said substrates on the side of said liquid crystal and said gap control film is removed at portions of said spacers arranged in regions other than said display region.
According to a further embodiment of the second embodiment of the liquid crystal display device of the present invention, for example, said spacers are arranged inside said display region as to avoid said boundary portion of each of said color filters.
The invention is not particularly limited to the constructions described above but can be changed or modified in various ways without departing from the technical concept thereof.